Reposting here, since it probably got lost in The Big Thread:


Huh, instead of a code question you ask a science question about silver.  At last I am in my element (if you'll pardon the pun)!

First of all, something I ran across while researching this that is just plain cool:

http://www.capturedlightning.com/frames/shrinkergallery.html

Here's somebody that talks about shrinkage while casting silver bullets:

http://www.patriciabriggs.com/articles/silver/silverbullet4.shtml

As far as cast silver shrinkage goes, here's a few other references for you to consider.  First, the shrinkage occurs in three stages:

http://thelibraryofmanufacturing.com/metalcasting_operation.html

Also, the thermal coefficient of expansion for silver varies with temperature, from 18.9 at room temp to 27.1 at 1100 K.  This says the first order approx for cubic vol expansion is roughly 3 times that which is 56.7 to 81.3 - in the range you were quoting:

http://www.kayelaby.npl.co.uk/general_physics/2_3/2_3_5.html

Next, this guy measured silver volume expansion in his lab setup in preparation for measuring a copper-iron alloy.  He got  2.56% on cooling and 3.58% on heating, against a tabulated value of 3.4-3.8%.  See pg 20 of the PDF, page 7 of the thesis:

http://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=1&cad=rja&uact=8&ved=0CCgQFjAA&url=http%3A%2F%2Fwww.diva-portal.org%2Fsmash%2Fget%2Fdiva2%3A218833%2FFULLTEXT01.pdf&ei=-AQhU_vTBsulkQeT4IHQDw&usg=AFQjCNFLhKymiTGSwBWr-prG1LsriM2udA&sig2=HEbEyhcf_FZMEzfRQqqPsQ&bvm=bv.62922401,d.eW0

The book he lists as Ref 32 (the 1976 edition of Smithells Metals Reference Handbook) is here:

http://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=2&cad=rja&uact=8&ved=0CC4QFjAB&url=http%3A%2F%2Fworldtracker.org%2Fmedia%2Flibrary%2FEngineering%2FMetallurgy%2FSmithells%2520Metals%2520Reference%2520Book%2520(7th%2520Edition).pdf&ei=gAchU9LyHdDSkQfRj4CoAQ&usg=AFQjCNGsZHjMhb-8NW473q7STxAsIM5raQ&sig2=3uvHS5OGsAXxnfkBCnIBQw&bvm=bv.62922401,d.eW0